Electroplating solution composition for organic polymer-zinc alloy composite plating and plated metal material using such composition

ABSTRACT

An object of the invention is to provide an electroplating solution composition capable of obtaining a plated film excellent in adhesiveness to a coated film and excellent in corrosion resistance without surface treatment. The present invention relates to an organic polymer composite zinc alloy electroplating solution composition containing: (A) 1 to 600 g/l of Zn ion, (B) 1 to 600 g/l of an iron-group-element ion, and (C) 0.1 to 200 g/l, in terms of W ion, of tungstic acid-based compound, and (D) 0.5 to 500 g/l of water-soluble or water-dispersible organic polymer compound having a number average molecular weight of 1,000 to 1,000,000.

TECHNICAL FIELD

The present invention relates to an organic polymer composite zinc alloyelectroplating solution composition for forming an electroplated filmhaving both roles of plating and surface treatment and also to anorganic polymer composite zinc alloy electroplated metal materialobtainable by electroplating using the composition.

BACKGROUND ART

As surface treatment of zinc-based plated metal materials for use inautomobiles, home electric appliances, building materials, and the like,treatment with a chromate salt and treatment with zinc phosphate aregenerally conducted but toxicity of chromium has been regarded as aproblem. The treatment with a chromium salt has problems that fumes ofthe chromate salt emit during the treating step, a large cost isrequired for waste water-treating facility, and chromic acid is elutedout of chemical conversion films. Further, hexavalent chromium compoundsare assigned as carcinogenic substances for human by many publicinstitutions including IARC (international Agency for Research on CancerReview) as a representative and are extremely toxic substances.

Additionally, in the treatment with zinc phosphate, since rinsetreatment with chromic acid is usually conducted after the treatmentwith zinc phosphate, there arise a problem of chromium treatment andalso problems of waste water treatment for a reaction accelerator, metalions, and the like in a zinc phosphate treating agent and sludgetreatment due to elution of metal ions from metals to be treated.

Furthermore, there is a strong need to reduce a cost for a coating line,so that it is desired to develop a plated film excellent in adhesivenessto a coating film without surface treatment and also excellent incorrosion resistance.

For these purposes, there have been developed methods of adding awater-soluble organic polymer into a zinc plating bath andco-precipitating the metal and the organic polymer at electroplating ametal material (e.g., see Patent Literatures 1 and 2).

However, a sufficient corrosion resistance is not obtained by mereaddition of a water-soluble organic polymer into a general plating bathand it is difficult to apply the methods to fields wherein a severecorrosion resistance is required, e.g., automobile field.

Patent Literature 1: JP 1-177394 A

Patent Literature 2: JP 7-56080 B

DISCLOSURE OF THE INVENTION

An object of the invention is to provide an electroplating solutioncomposition capable of obtaining a plated film excellent in adhesivenessto a coating film without surface treatment and excellent in corrosionresistance.

As a result of extensive studies for solving the above-describedproblems, the present inventors have found that corrosion resistance ofa plated film is remarkably improved by incorporating aniron-group-element ion and W ion into an organic polymer composite zincalloy electroplating solution containing Zn ion and a water-solubleand/or water-dispersible organic polymer, and they have accomplished theinvention.

Thus, the invention relates to an organic polymer composite zinc alloyelectroplating solution composition containing:

(A) 1 to 600 g/l of Zn ion,

(B) 1 to 600 g/l of an iron-group-element ion,

(C) 0.1 to 200 g/l, in terms of W ion, of tungstic acid-based compound,and

(D) 0.5 to 500 g/l of water-soluble or water-dispersible organic polymercompound having a number average molecular weight of 1,000 to 1,000,000.

Further, the invention relates to an organic polymer composite zincalloy electroplated metal material, which is obtainable byelectroplating an iron raw material using the above-described organicpolymer composite zinc alloy electroplating solution composition.

Furthermore, the invention relates to a fingerprint-resistant steelplate wherein an organic resin film is directly formed on the organicpolymer composite zinc alloy electroplated metal material withoutsurface treatment.

In addition, the invention relates to a lubricating steel plate whereinan organic resin film having a lubricating function is directly formedon the above-described organic polymer composite zinc alloyelectroplated metal material without surface treatment.

BEST MODE FOR CARRYING OUT THE INVENTION

The organic polymer composite zinc alloy electroplating solutioncomposition (hereinafter referred to as an electroplating solutioncomposition) of the invention contains Zn ion (A), an iron-group-elemention (B), a tungstic acid-based compound (C), and a water-soluble orwater-dispersible organic polymer compound (D) as essential components.

“Zn ion (A)”

The Zn ion as component (A) of the electroplating solution compositionof the invention constitutes a main component of the plated layer.

The Zn ion is added to the plating bath in a form of chloride, sulfate,fluoride, cyanide, oxide, an organic acid salt, a phosphate salt, orelementary metal.

“Iron-Group-Element Ion (B)”

The iron-group element generally means nickel, cobalt, or iron. Theiron-group-element ion as component (B) of the electroplating solutioncomposition of the invention is selected from Ni ion, Co ion, and Feion. Of these, Fe ion is preferred in view of corrosion resistance.

The iron-group-element ion (B) is added to a plating bath in a form ofchloride, sulfate, fluoride, cyanide, oxide, an organic acid salt, aphosphate salt, or elementary metal.

“Tungstic Acid-Based Compound (C)”

The tungstic acid-based compound as component (C) of the electroplatingsolution composition of the invention can remarkably improve corrosionresistance of the plated layer obtained by combination with an organicpolymer compound (D).

Examples of the tungstic acid-based compound (C) include tungstic acid,tungstate salts, phosphotungustic acid, and phosphotungstate salts.Examples of the salts include ammonium salts, potassium salts, calciumsalts, sodium salts, and the like. Particularly, ammonium salts orsodium salts are preferred. Of these, ammonium tungstate, ammoniumphosphotungstate, sodium tungstate, and sodium phosphotungstate arepreferred in view of corrosion resistance.

“Water-Soluble or Water-Dispersible Organic Polymer Compound (D)”

The water-soluble or water-dispersible organic polymer compound ascomponent (D) of the electroplating solution composition of theinvention is selected from those chemically stable even when it is mixedwith the above-described metal ions. By adding the organic polymercompound to the plating solution, adhesiveness between a plated filmobtained therefrom and an organic resin film formed on the plated filmis remarkably improved and thus a sufficient corrosion resistance can beobtained without chemical conversion treatment of the plated film with asurface treating agent such as zinc phosphate or a chromate.

As the organic polymer compound (D), those having a water-solubleproperty or a water-dispersible property (the manner of dispersion maybe either suspension or emulsion) can be used. As a method forsolubilizing, dispersing, or emulsifying the organic polymer compound inwater, a conventionally known method can be used. As the water-solubleor water-dispersible organic polymer compound, preferred are thosehaving at least one hydrophilic group selected from the group consistingof nonionic hydrophilic groups, anionic hydrophilic groups and cationichydrophilic groups. Specifically, there can be used those containing afunctional group independently capable of solubilizing or dispersing itin water (e.g., at least one of a hydroxyl group, a carboxyl group, anamino (imino) group, a sulfonic acid group, a phosphoric acid group, orthe like), those neutralized with part or all of those functional groupswith an amine compound such as ethanolamine or triethylamine, ammoniawater, an alkali metal hydroxide such as lithium hydroxide, sodiumhydroxide, or potassium hydroxide in the case of acidic resins such ascarboxyl group-containing resins or with a fatty acid such as aceticacid or lactic acid or a mineral acid such as phosphoric acid in thecase of basic resins such as amino group-containing resins, and thelike.

Examples of such an organic polymer compound (D) include epoxy resins,phenolic resins, acrylic resins, urethane resins, olefin-carboxylic acidresins, nylon resins, polyvinyl alcohol, resins having a polyoxyalkylenegroup, polyethylene glycol, polyglycerin, carboxymethy cellulose,hydroxymethyl cellulose, hydroxyethyl cellulose, and the like.

As the above-described epoxy resins, use can be preferably made ofcationic epoxy resins obtainable by adding an amine to epoxy resins;modified epoxy resins such as acryl-modified ones and urethane-modifiedones; and the like. Examples of the cationic epoxy resins includeadducts of epoxy compounds with a primary mono- or polyamine, asecondary mono- or polyamine, or a primary and secondary mixed polyamine(e.g., see U.S. Pat. No. 3,984,299); adducts of epoxy compounds with asecondary mono- or polyamine having ketiminated primary amino group(e.g., see U.S. Pat. No. 4,017,438); etherified reaction products ofepoxy compounds with a hydroxyl compound having a ketiminated primaryamino group (e.g., see JP 59-43013 A); and the like.

As the above-described epoxy compounds, suitable are those having anumber average molecular weight of within the range of 400 to 4,000,particularly 800 to 2,000 and an epoxy equivalent of within the range of190 to 2,000, particularly 400 to 1,000. Such epoxy compounds can be,for example, obtained by reacting polyphenol compounds withepichlorohydrin. Examples of the polyphenol compounds includebis(4-hydroxyphenyl)-2,2-propane, 4,4-dihydroxybenzophenone,bis(4-hydroxyphenyl)-1,1-ethane, bis(4-hydroxyphenyl)-1,1-isobutane,bis(4-hydroxy-tert-butylphenyl)-2,2-propane,bis(2-hydroxynaphthyl)methane, 1,5-dihydroxynaphthalene,bis(2,4-dihydroxyphenyl)methane, tetra(4-hydroxyphenyl)-1,1,2,2-ethane,4,4-dihydroxydiphenyl sulfone, phenol novolak, cresol novolak, and thelike.

As the phenolic resin, use can be suitably made of a water-solubilizedcompound from a polymer compound obtained by heating a phenol componentand a formaldehyde in the presence of a reaction catalyst to effectaddition and condensation. As the above-described phenol component as astarting material, a bifunctional phenol compound, trifunctional phenolcompound, or tetrafunctional or polyfunctional phenol compound can beused. Examples thereof include o-cresol, p-cresol, p-tert-butylphenol,p-ethylphenol, 2,3-xylenol, and 2,5-xylenol as the bifunctional phenolcompounds, phenol, m-cresol, m-ethylphenol, 3,5-xylenol, andm-methoxyphenol as trifunctional phenol compounds, and bisphenol A,bisphenol F as tetrafunctional phenol compounds. These phenol compoundsmay be used solely or as a mixture of two or more of them.

Examples of the above-described acrylic resins include homopolymers orcopolymers of monomers each having a hydrophilic group such as acarboxyl group, an amino group, or a hydroxyl group, copolymers ofmonomers each having a hydrophilic group with the other copolymerizablemonomers. They are resins obtainable by emulsion polymerization,suspension polymerization, or solution polymerization and, if necessary,by neutralizing or making it hydrophilic the resulting resins or bymodifying the resins.

Examples of the above-described carboxyl group-containing monomerinclude acrylic acid, methacrylic acid, maleic acid, maleic anhydride,crotonic acid, itaconic acid, and the like.

Examples of a nitrogen-containing monomer include nitrogen-containingalkyl(meth)acrylates such as N,N-dimethylaminoethyl(meth)acrylate,N,N-diethylaminoethyl (meth)acrylate, andN-t-butylaminoethyl(meth)acrylate; polymerizable amides such asacrylamide, methacrylamide, N-methyl(meth)acrylamide,N-ethyl(meth)acrylamide, N-methylol(meth)acrylamide,N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide,N,N-dimethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide,and N,N-dimethylaminoethyl(meth)acrylamide; aromatic nitrogen-containingmonomers such as 2-vinylpyridine, 1-vinyl-2-pyrrolidone, and4-vinylpyridine; allylamine, and the like.

Examples of the hydroxyl group-containing monomer include monoestercompounds of acrylic acid or methacrylic acid with polyhydric alcohols,such as 2-hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate,2,3-dihydroxybutyl(meth)acrylate, 4-hydroxybutyl (meth)acrylate, andpoly(ethylene glycol) mono(meth)acrylate; compounds obtained byring-opening polymerization of ε-caprolactone to the above-describedmonoester compounds of acrylic acid or methacrylic acid with polyhydricalcohols; and the like.

Examples of the other monomers include alkyl (meth)acrylates having 1 to24 carbon atoms, such as methyl(meth)acrylate, ethyl(meth)acrylate,n-propyl (meth)acrylate, isopropyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, tert-butyl (meth)acrylate,2-ethylhexyl(meth)acrylate, n-octyl (meth)acrylate,lauryl(meth)acrylate, tridecyl (meth)acrylate, octadecyl(meth)acrylate,and isostearyl (meth)acrylate; styrene, vinyl acetate, and the like.These compounds may be used solely or as a mixture of two or more ofthem. In the invention, “(meth)acrylate” means acrylate or methacrylate.

As the above-described urethane resins, use can be suitably made ofthose obtained by chain-extension of polyurethanes each composed of apolyol such as a polyester polyol or a polyether polyol and adiisocyanate in the presence of a chain-extending agent which is alow-molecular-weight compound having two or more active hydrogens, suchas a diol or a diamine and by dispersing or dissolving the productsstably in water, and known ones can be widely used (e.g., see JP42-24192 A, JP 42-24194 A, JP 42-5118 B, JP 49-986 B, JP 49-33104 B, JP50-15027 B, and JP 53-29175 B). As methods for dispersing or dissolvingthe polyurethane resins stably in water, the following methods can beutilized, for example.

(1) A method of imparting hydrophilicity by introducing an ionic groupsuch as a hydroxyl group, an amino group, or a carboxyl group into theside chain or the terminal of a polyurethane polymer and dispersing ordissolving it in water by self-emusification.

(2) A method of blocking a reaction-completed polyurethane polymer or aterminal isocyanate group with a blocking agent such as an oxime, analcohol, a phenol, a mercaptan, an amine, or sodium bisulfite anddispersing the blocked polyurethane polymer in water by force using anemulsifier and a mechanical shear force. Further, a method of mixing aurethane polymer having a terminal isocyanate group with water/anemulsifier/a chain-extending agent and achieving simultaneous dispersionand increase of the molecular weight using a mechanical shear force.

(3) A method of dispersing or dissolving a polyurethane as awater-soluble polyurethane using a water-soluble polyol such aspolyethylene glycol as a polyol of a main material for the polyurethane.

With regard to the above-described polyurethane resin, theabovementioned method of dispersion or dissolution is not limited to asingle method and a mixture obtained by each method can be alsoempolyed.

Examples of the diisocyanate usable for synthesis of the above-describedpolyurethane resins include aromatic, alicyclic and aliphaticdiisocyanates, and specifically include hexamethylene diisocyanate,tetramethylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylenediisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate,1,3-(diisocyanatomethyl)cyclohexanone,1,4-(diisocyanatomethyl)cyclohexanone, 4,4′-diisocyanatocyclohexanone,4,4′-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate,2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylenediisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate,2,4-naphthalene diisocyanate, 3,3′-dimethyl-4,4′-biphenylenediisocyanate, 4,4′-biphenylene diisocyanate, and the like. Of these,particularly preferred are 2,4-tolylene diisocyanate, 2,6-tolylenediisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

Examples of commercial products of the above-described polyurethaneresins include HYDRAN HW-330, HW-340, HW-350 (all manufactured byDainippon Ink And Chemicals, Inc.), SUPERFLEX 100, 150, F-3438D (allmanufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and the like.

The above-described polyvinyl alcohol resin is preferably polyvinylalcohol having a saponification degree of 87% or more, particularlyso-called completely saponified polyvinyl alcohol having asaponification degree of 98% or more. Further, its number averagemolecular weight is suitably within the range of 3,000 to 100,000.

As the above-described resin having a polyoxyalkylene chain, a resinhaving a polyoxyethylene chain or a polyoxypropylene chain can besuitably used and examples thereof include polyethylene glycol,polypropylene glycol, blocked polyoxyalkylene glycols wherein thepolyoxyethylene chain and the polyoxypropylene chain are combined in ablock form, and the like.

As the above-described olefin-carboxylic acid resin, use can be made ofat least one water-dispersible or water-soluble resin selected from twokinds, i.e., a copolymer of an olefin such as ethylene or propylene witha polymerizable unsaturated carboxylic acid and a resin obtained byadding a polymerizable unsaturated compound to dispersion of thecopolymer to effect emulsion polymerization and further subjecting theproduct to intraparticle crosslinking.

The above-described copolymer is a copolymer of an olefin with one ortwo or more kinds of polymerizable unsaturated carboxylic acids such as(meth)acrylic acid and maleic acid. In the copolymer, it is suitablethat the content of the unsaturated carboxylic acid is within the rangeof 3 to 60% by weight, preferably 5 to 40% by weight and the copolymercan be dispersed in water by neutralizing the acid group in thecopolymer with a basic substance.

The number average molecular weight of the water-soluble orwater-dispersible organic polymer compound (D) usable in the inventionin terms of polystyrene using a GPC (gel permeation chromatograph)measuring method is within the range of 1,000 to 1,000,000, particularly2,000 to 500,000 in view of adhesiveness with the organic resin film andstorage stability of the plating solution.

Further, it is preferred to add a complexing agent to the platingsolution for the purpose of stabilizing the metal ions in the platingsolution. The complexing agent can be selected from the group consistingof oxycarboxylate salts such as citrate salts, tartrate salts, andgluconate salts, aminoalcohols such as monoethanolamine, diethanolamine,and triethanolamine, polyamines such as ethylenediamine (EDA),diethylenetriamine, and triethylenetetramine, aminocarboxylate saltssuch as ethylenediamine tetraacetate salts and nitroacetate salts,polyhydric alcohols such as sorbit and pentaerythritol, and mixturesthereof.

In the invention, functions of high corrosion resistance, coatingadhesiveness, and the like can be imparted by combining acorrosion-inhibiting pigment and/or ceramic particles capable of beingprecipitated as discontinuous particles from the electroplatingsolution.

As the above-described corrosion-inhibiting pigment, a generally knownone can be used and preferred examples thereof include phosphate salts,molybdate salts, metaborate salts, silicate salts, and the like.Further, examples of the ceramic particles include particles of oxidessuch as Al₂O₃, SiO₂, TiO₂, ZrO₂, Y₂O₂, ThO₂, CeO₂, and Fe₂O₃; carbidessuch as B₄C, SiC, WC, ZrC, TiC, graphite, and graphite fluoride;nitrides such as BN, Si₃N₄, and TiN; borides such as Cr₃B₂, and ZrB₂;silicate salts such as 2MgO.SiO₂, MgO.SiO₂, and ZrO₂.SiO₂, and the like.The mixing amount of the corrosion-inhibiting pigment and/or ceramicparticles is desirably within the range of 5 to 300 g per liter of theplating bath. Further, the smaller the particle size is, the moreexcellent dispersion stability is. Therefore, ultrafine particles havinga size of 1 μm or less are preferred. Furthermore, it is desirable tocontrol co-precipitated amount in the plating matrix to the range of 1to 30% by weight, particularly 1 to 10% by weight per total precipitatedamount. When the co-precipitated amount is small, an effect of improvingcorrosion resistance is not exhibited and when it exceeds 30% by weight,plated film becomes brittle and also adhesiveness with the base materialdecreases, so that the cases are problematic.

In order to improve corrosion resistance, a corrosion-inhibiting organiccompound may be further added to the plating bath. Examples ofpreferable corrosion-inhibiting organic compound include alkynes,alkynols, amines or salts thereof, thio compounds, aromatic carboxylicacid compounds or salts thereof, and heterocyclic compounds, and thelike.

Of these, the alkynes mean organic compounds containing a carbon-carbontriple bond and examples thereof include pentyne, hexyne, heptyne,octyne, and the like. The alkynols mean organic compounds having one ormore hydroxyl group in the alkynes and examples thereof includepropargyl alcohol, 1-hexyn-3-ol, 1-heptyn-3-ol, and the like. The aminesmean organic compounds containing one or more nitrogen atoms in themolecule, which include any of aliphatic or aromatic compounds. Examplesof such amines include octylamine, nonylamine, decylamine, laurylamine,tridecylamine, cetylamine, and the like. The thio compounds mean organiccompounds containing one or more sulfur atoms in the molecule andexamples of such thio compounds include decyl mercaptan, cetylmercaptan, thiourea, and the like. The heterocyclic compounds meanorganic compounds containing atom(s) other than a carbon atom asring-constituting atoms in a cyclic molecule and examples of suchheterocyclic compounds include pyridine, benzothiazole, benzotriazole,quinoline, indole, and the like. Further, examples of the aromaticcarboxylic acid compound include benzoic acid, salicylic acid, toluicacid, naphthalenecarboxylic acid, and the like. With regard to theamines or carboxylic acid compounds, it is possible to use a saltthereof, and an equivalent effect can also be obtained thereby. Saltsthat can be used include, for the case of amines, acid addition saltssuch as sulfates and hydrochlorides, and for the case of the aromaticcarboxylic acid compounds, metal salts such as alkali metal salts andzinc salts, and ammonium salts.

The amount of the corrosion-inhibiting organic compound to be added tothe plating bath is desirably regulated to 0.1 to 10% by weight in thecase of the alkynes or alkynols, 3 to 10% by weight in the case of theamines or salts thereof, 0.2 to 5% by weight in the case of the thiocompounds, 1 to 10% by weight in the case of the heterocyclic compounds,and 3 to 8% by weight in the case of the aromatic carboxylic acidcompounds or salts thereof. Further, it is possible to incorporate, intothe plating solution, additive(s) usually used for the purpose ofimproving burnt deposit at a high current density or throwing power at alow current density. Examples thereof include a reaction product of anamine with an epihalohydrin, polyethylenepolyamine, the other quaternaryamine polymer, urea, thiourea, gelatin, polyvinyl alcohol, an aldehyde,and the like.

“Electroplating Solution Composition”

The electroplating solution composition of the invention contains Zn ion(A), an iron-group-element ion (B), a tungstic acid-based compound (C),and a water-soluble or water-dispersible organic polymer compound (D) asessential components. Examples of the electroplating bath usable include(1) acidic baths such as a sulfate bath using zinc sulfate, a chloridebath using zinc chloride, and a borofluoride bath using zincborofluoride, (2) neutral baths wherein zinc chloride is neutralizedwith ammonia, potassium chloride, or the like, (3) alkaline baths suchas a pyrophosphate bath using zinc pyrophosphate, a zincate bathcomprising zinc and sodium hydroxide, and the like. With regard to thecontents of the components in the electroplating solution composition,suitable is those containing Zn ion (A) of 1 to 600 g/l, preferably 50to 300 g/l, more preferably 60 to 250 g/l, an iron-group-element ion (B)of 1 to 600 g/l, preferably 50 to 300 g/l, more preferably 60 to 250g/l, a tungstic acid-based compound (C) of 0.1 to 200 g/l, preferably 5to 150 g/l, more preferably 10 to 100 g/l in terms of W ion, and awater-soluble or water-dispersible organic polymer compound (D) of 0.5to 500 g/l, preferably 10 to 300 g/l, more preferably 20 to 200 g/l assolid matter, in view of coated film adhesiveness to a plating andcorrosion resistance.

To the electroplating solution composition of the invention, acomplexing agent for stabilizing metal ions, a corrosion-inhibitingpigment and/or ceramic particles capable of being precipitated asdiscontinuous particles from the electroplating solution for the purposeof further improving corrosion resistance, a corrosion-inhibitingorganic compound, and the like can be added. In addition, to theabove-described electroplating solution composition, it is possible touse additive(s) usually used for the purpose of improving burnt depositat a high current density or throwing power at a low current density,such as a pH regulator, a pit inhibitor, a mist suppressant, antifoamingagent, and the like.

The electroplating solution composition of the invention can form aplated film excellent in coated film adhesiveness, corrosion resistance,and the like through co-precipitation of the organic polymer compoundand the metal by electroplating in a similar manner to a conventionalmethod.

As conditions for electroplating, it is suitable that pH is about 1 to 3and a bath temperature is about 30 to 80° C. in case that the platingbath is a sulfate bath, pH is about 4 to 7 and a bath temperature isabout 10 to 50° C. in case that the plating bath is a chloride bath, andpH is 12 or higher and a bath temperature is about 10 to 50° C. in casethat the plating bath is an alkaline bath, and the thickness of theplated film is suitably from about 0.5 to 5 μm in all cases.

“Electroplated Metal Material”

The plated metal material of the present invention is obtained byelectroplating a metal raw material using the above-describedelectroplating solution composition. The metal raw material includesmaterials mainly comprising iron, e.g., materials for automobiles, homeelectric appliances, and building materials, processed into a shape of aplate, tube, joint, clamp, bolt, nut or the like.

The electroplating conditions are as described above. Further, theadvantages of the invention can be further enhanced by post-treatmentwith an acidic aqueous solution of a compound containing at least oneelement selected from the group consisting of cobalt, nickel, titanium,and zirconium after the formation of the electroplated film. As thecompound containing at least one element selected from the groupconsisting of cobalt, nickel, titanium and zirconium, usable examplesinclude oxides, hydroxides, fluorides, complex fluorides, chlorides,nitrates, sulfates, carbonates, etc. of these metals. Specifically,preferred examples thereof include cobalt nitrate, zirconium oxynitrate,titanium hydrofluoride, zirconium hydrofluoride, ammonium titaniumhydrofluoride, and ammonium zirconium hydrofluoride.

The acidic aqueous solutions of the compounds containing these metalelements preferably has a pH falling within the range of from 1 to lessthan 7, preferably from 3 to 6. The pH can be adjusted by an acid suchas hydrochloric acid, nitric acid, sulfuric acid and hydrofluoric acid,or a base such as sodium hydroxide, potassium hydroxide and amines.Further, a complexing agent, silica particles, etc. may be added to theacidic aqueous solution as needed. The amount of the compound containingthe metal element to be added is preferably from 0.001 to 5 mol/liter,and particularly preferably about 0.01 to 1 mol/liter.

The post-treatment with the acidic aqueous solution can be carried outby bringing the electroplated film into contact with the processingsolution, for example by immersing the metal material into theprocessing solution of a bath temperature of 20 to 80° C., preferably 30to 60° C., for 5 seconds or longer, preferably about 20 to 90 seconds.

Since the electroplated metal material obtained as above is excellent incoated film adhesiveness, a coating material can be applied directly tothe material without particular surface treatment. Further, even when itis combined with a chromium-free environment-responsive surface-treatingagent, it exhibits an excellent corrosion resistance.

The coating material in the case of coating the electroplated metalmaterial of the invention is not particularly limited, any curing modesuch as room-temperature drying, hot curing, or active energy ray-curingcan be employed, and any kind of coating materials such as solvent-typecoating materials, water-based coating materials, and powdered coatingmaterials may be used. Particularly, in the case that the electroplatingsolution composition of the invention is applied to automobiles,generally, an electrodeposition paint, an intermediate coat, and a topcoat are sequentially applied on the plated film and then baked.

Since the electroplated metal material of the invention is excellent incorrosion resistance, it is possible that an organic resin film isformed directly on a non-treated tabular electroplated metal material,thereby serving the use as a fingerprint-resistant steel plate. Further,by imparting the lubricating property to the above-described organicresin film, the resulting product can be used as a lubricating steelplate.

The fingerprint-resistant steel plate is a steel plate having a thinorganic resin film formed thereon for preventing generation of rustduring the period until the steel plate is used. The organic resinforming the organic resin film is not particularly limited. Examples ofsuitable resins include polyurethane resins, epoxy resins, acrylicresins, polyester resins, phenolic resins, polyolefin resins, alkydresins, melamine resins, polybutyral resins, and the like. The organicresin may be a solvent-type resin dissolved in an organic solvent but,if possible, an aqueous resin dissolved or dispersed (suspended oremulsified) in water, particularly an emulsion resin is preferred.

In the above-described organic film, silica particles may be added inorder to improve adhesiveness and corrosion resistance of the film. Asthe silica particles, water-dispersible colloidal silica is suitable butvapor-phase-process silica and pulverized silica can be also used. Theremay be mentioned SNOWTEX N, SNOWTEX C, SNOWTEX O (all manufactured byNissan Chemical Industries, Ltd.), and the like as the water-dispersiblecolloidal silica and AEROSIL 200V, AEROSIL R-811 (all manufactured byNippon Aerosil Co., Ltd.), and the like as the other silica particles.

The lubricating metal material is a steel plate to which a lubricatingproperty is preliminarily imparted, so that processing such aspress-molding can be carried out without coating a press oil, forsuppressing the use of a solvent unfavorable from the standpoint ofglobal environmental preservation such as chlorofluorocarbon,1,1,1-trichloroethane used in a press oil-washing step after molding andprocessing a steel plate. Usually, a lubricating function-impartingagent is incorporated in the organic resin film used for afingerprint-resistant steel plate or the like, thereby making alubricating film formed on a steel plate. The lubricatingfunction-imparting agent is preferably an agent which imparts alubricating (friction coefficient-reducing) function to the film and isnot colored by baking. Examples of a preferable lubricatingfunction-imparting agent include polyolefin waxes such as polyethyleneand polypropylene; fluorine-based waxes such as tetrafluoroethyleneresin (PTFE), chlorotrifluoroethylene resin, vinylidene fluoride resin,vinyl fluoride resin, ethylene/tetrafluoroethylene copolymer resin, andtetrafluoroethylene/hexafluoropropylene copolymer resin, and the like.They may be used solely or as a mixture of two or more of them.

The thickness of the organic resin film having fingerprint resistanceand lubricity is from about 0.5 to 5 μm and may be a colored filmcontaining a dye or pigment. Further, since surface treatment can beomitted, a production process can be remarkably shortened and operatingefficiency can be improved by incorporating a coating step for formingthe organic resin film into a production line of the electroplated steelplate.

In the case that the electroplated metal material of the invention issubjected to surface treatment, the treatment can be conducted with achromate-based surface treating agent or phosphate salt-based surfacetreating agent. Since the electroplated metal material of the inventionis excellent in corrosion resistance, an excellent corrosion resistanceis also exhibited by combination with a chromium-freeenvironment-responsive surface-treating agent such as a zirconium-basedsurface treating agent or a titanium-based surface-treating agent. Inorder to reduce an environmental load, preferred is the combination witha chromium-free environment-responsive surface-treating agent.

The coated metal material can be used in applications where coated metalmaterials are conventionally used, such as building material, homeelectric appliances, automobiles, fastening parts, and the like, withoutparticular limitation. The methods for applying the under coat and topcoat may be suitably selected according to the application, the shape ofan article to be coated, and the like. For example, spraying, dipping,electrodeposition, or the like is suitable in the case of coating ofmolded articles and roll coating, curtain flow coating, or the like issuitably employed in the case of coating of plate-type articles such aspre-coated metal materials.

EXAMPLES

The present invention will be illustrated in greater detail withreference to the following Examples. In this connection, the “part(s)”and “%” used below are all given by weight.

“1. Preparation of Plating Solution and Manufacture of ElectroplatedMetal Material”

Examples 1 to 15 and Comparative Examples 1 to 3

Each plating solution was obtained according to the blend compositionshown in Table 1 below.

A cold-rolled metal material (SPCC) having a plate thickness of 0.8 mmwas subjected to alkaline degreasing and washed with water, and then itwas plated under the following conditions using each of theabove-described plating solution.

Plating conditions: plating was conducted at a bath temperature of therange of 30 to 60° C. using a direct current having a current density of1 to 30 A/dm². The thickness of a plated film was 3 μm in all cases. Thefilm thickness was measured on a fluorescent X-ray analyzer SEA5200(manufactured by Seiko Instruments Inc.). TABLE 1 Corrosion inhibitor*³Electro- Metal ion*¹ (g/L) Organic resin*² (g/l) (g/l) plated steel ZnFe Co Ni W R1 R2 R3 R4 R5 F1 F2 F3 plate No. Example 1 82 79 10 20 A1 293 60 10 40 A2 3 78 75 10 20 A2 4 78 75 20 40 A4 5 78 75 20 40 A5 6 7875 20 120 A6 7 62 90 20 80 A7 8 155  150  30 20 A8 9 232  225  40 40 A910  146  142  60 80 A10 11  129  125  80 150 A11 12  112  106  100  200A12 13  78 75 10 40 30 A13 14  78 75 20 40 20 A14 15  78 75 20 40 1 A15Comparative example 1 90 80 20 B1 2 170  20 40 B2 3 170  20 40 B3*1: Respective metal ions in Table 1 are supplied from the followingcompounds.

Zn: ZnSO₄.7H₂O

Fe: FeSO₄.7H₂O

Co: CoSO₄.7H₂O

Ni: NiSO₄.7H₂O

W: Na₂WO₄.2H₂O

*2: Respective organic resins in Table 1 are those shown below.

R1: Sodium lignin sulfonate, number average molecular weight of about10,000.

R2: Na salt of a sulfonated product of a novolak-type phenol resin,number average molecular weight of about 23,000.

R3: Na salt of a sulfonated product of a novolak-type phenol resin,number average molecular weight of about 40,000.

R4: Na salt of a sulfonated product of poly-p-hydroxystyrene, numberaverage molecular weight of about 5,000.

R5: Na salt of a sulfonated product of a bisphenol A-type epoxy resin,number average molecular weight of about 7,000.

*3: Respective corrosion inhibitors in Table 1 are those shown below.

F1: K-WHITE 840E, manufactured by Tayca Corporation, condensed aluminumphosphate.

F2: SNOWTEX-O, manufactured by Nissan Chemical Industries, Ltd.,colloidal silica.

F3: 3-Amino-1,2,4-triazole.

“2. Coating System 1”

Examples 16 to 30 and Comparative Examples 4 to 6

Each surface of the plated metal materials obtained in the above-shownTable 1 was subjected to alkaline degreasing, washed with water,drained, and dried. Thereafter, “MAGICRON 1000 white” (manufactured byKansai Paint Co., Ltd., an acryl-melamine resin-based coating, white)was applied thereto so that a dry film thickness became 30 μm, and bakedat 160° C. for 20 minutes to obtain each test coated plate.

Comparative Example 7

To steel plate (SECC material with a plating deposition amount of 20g/m²: JIS G-3313) having a plate thickness of 0.8 mm and treated with aphosphate salt (trade name: Palbond 3118, manufactured by NihonParkerizing Co., Ltd.), “MAGICRON 1000 white” (manufactured by KansaiPaint Co., Ltd., an acryl-melamine resin-based coating, white) wasapplied thereto so that a dry film thickness became 30 μm, and baked at160° C. for 20 minutes to obtain a test coated plate.

On respective test coated plates obtained in the above Examples andComparative Examples, various tests were carried out in accordance withthe following test methods. The results are shown in Table 2 below.

(Top coat adhesiveness): After each test coated plate was dipped in aboiling water of about 98° C. for 2 hours, it was taken out and allowedto stand at room temperature for 2 hours and then the coated surface ofthe test coated plate was cut by a knife so as to result in each 11 cutsreaching the base metal lengthwise and crosswise in a grid pattern,whereby 100 blocks having 2 mm square were formed. Peeled area of thecoated film was evaluated according to the following standards at thetime when a cellophane adhesive tape was closely adhered to the gridpart and the tape was peeled off instantaneously.

5: No peeling of the coated film is observed.

4: Peeling of the coated film is observed but peeled area is less than10%.

3: Peeled area is from 10% to less than 25%.

2: Peeled area is from 25% to less than 50%.

1: Peeled area is 50% or more.

(Corrosion resistance after coating): A crosscut reaching the base metalwas incised on each test coated plate, which was subjected to salt spraytest for 240 hours in accordance with JIS Z-2371. Thereafter, the testcoated plate was washed with water and dried. Then, a cellophaneadhesive tape was closely adhered to the crosscut part and a maximumpeeled width (one side, m) from the crosscut part was measured when thetape was peeled off instantaneously. TABLE 2 Test results Corrosionresistance Electroplated steel Top coat after coating plate No.adhesiveness (one side, mm) Example 16 A1 5 3 17 A2 5 2 18 A2 5 2 19 A45 2 20 A5 5 3 21 A6 5 2 22 A7 5 4 23 A8 5 4 24 A9 5 3 25  A10 5 2 26 A11 5 2 27  A12 5 2 28  A13 5 2 29  A14 5 2 30  A15 5 2 ComparativeExample  4 B1 2 5  5 B2 4 7  6 B3 5 5  7 4 7“3. Coating System 2”

Examples 31 to 45 and Comparative Examples 8 to 10

Each of the plated metal materials obtained in the above-shown Table 1was subjected to degreasing, washed with water, drained, and dried.Thereafter, a cation-type electrodeposition coating “ELECRON GT-10”(manufactured by Kansai Paint Co., Ltd., an epoxypolyester resin-basedone) was applied by electrodeposition coating and baked at 170° C. for20 minutes to obtain an electrodeposition-coated plate having a dry filmthickness of 20 μm. An intermediate coat “AMILAC TP-65 gray”(manufactured by Kansai Paint Co., Ltd., an aminoalkyd resin-based one)was applied to the electrodeposition-coated surface using a spray sothat a dry film thickness became 30 μm, and baked at 140° C. for 20minutes. Thereafter, a top coat “NEO AMILAC #6000 white” (manufacturedby Kansai Paint Co., Ltd., an aminoalkyd resin-based one) was appliedusing a spray so that a dry film thickness became 30 μm, and baked at140° C. for 20 minutes to obtain each test coated plate.

Comparative Example 11

To an alloying hot dip galvanized steel plate (SGCC F06 material: JISG-3302) having a plate thickness of 0.8 mm and treated with a phosphatesalt (trade name: Palbond 3020, manufactured by Nihon Parkerizing Co.,Ltd.), a cation-type electrodeposition coating “ELECRON GT-10”(manufactured by Kansai Paint Co., Ltd., an epoxypolyester resin-basedone) was applied by electrodeposition coating and baked at 170° C. for20 minutes to obtain an electrodeposition-coated plate having a dry filmthickness of 20 μm. An intermediate coat “AMILAC TP-65 gray”(manufactured by Kansai Paint Co., Ltd., an aminoalkyd resin-based one)was applied to the electrodeposition-coated surface using a spray sothat a dry film thickness became 30 μm, and baked at 140° C. for 20minutes. Thereafter, a top coat “NEO AMILAC #6000 white” (manufacturedby Kansai Paint Co., Ltd., an aminoalkyd resin-based one) was appliedusing a spray so that a dry film thickness became 30 μm, and baked at140° C. for 20 minutes to obtain a test coated plate.

On respective test coated plates obtained in the above Examples andComparative Examples, various tests were carried out in accordance withthe following test methods. The results are shown in Table 3 below.

(Chipping resistance): A test coated plate was fixed on a test pieceholder of a gravel chipping test instrument JA-400 Model (a chippingtest apparatus manufactured by Suga Test Instruments Co., Ltd.) at aright angle relative to its gravel spout. Then, the coated surface wasblasted with 50 g of crushed granite having a No. 7 particle size at−20° C. by compressed air of 0.294 MPs (3 kgf/cm²) and generated chipson the coated film were visually observed and evaluated according to thefollowing standards.

AA: The size of chips is considerably small and only the top coat isbruised.

A: The size of chips is small and only the intermediate coat is exposed.

B: The size of chips is small but the metal material of base metal isexposed.

C: The size of chips is considerably large and the metal material ofbase metal is exposed to a large extent.

(Water-resistant secondary adhesiveness): After each test coated platewas dipped in warm water of 40° C. for 10 days, the coated surface ofthe test coated plate was cut by a knife so as to result in each 11 cutsreaching the base metal lengthwise and crosswise in a grid pattern,whereby 100 blocks having 2 mm square were formed. Peeled area of thecoated film was evaluated according to the following standards at thetime when a cellophane adhesive tape was closely adhered to the gridpart and the tape was peeled off instantaneously.

5: No peeling of the coated film is observed.

4: Peeling of the coated film is observed but peeled area is less than10%.

3: Peeled area is from 10% to less than 25%.

2: Peeled area is from 25% to less than 50%.

1: Peeled area is 50% or more.

(Corrosion resistance): A crosscut reaching the base metal was incisedon each test coated plate and it was subjected to salt spray test for960 hours in accordance with JIS Z-2371. Thereafter, the test coatedplate was washed with water and air-dried. Then, rust and swelling at ageneral part were evaluated according to the following standards as wellas a cellophane adhesive tape was closely adhered to the crosscut partand a maximum peeled width (one side, m) from the crosscut part wasmeasured when the tape was peeled off instantaneously.

A: No generation of rust and swelling on the coated surface is observed.

B: Slight generation of rust and swelling on the coated surface isobserved.

C: Remarkable generation of rust and swelling on the coated surface isobserved.

(Salt water resistance): A crosscut reaching the base metal was incisedon each test coated plate and it was dipped in 5% saline at 50° C. for10 days. Thereafter, the test coated plate was washed with water andair-dried. Then, rust and swelling at a general part were evaluatedaccording to the following standards as well as a cellophane adhesivetape was closely adhered to the crosscut part and a maximum peeled width(one side, m) from the crosscut part was measured when the tape waspeeled off instantaneously.

A: No generation of rust and swelling on the coated surface is observed.

B: Slight generation of rust and swelling on the coated surface isobserved.

C: Remarkable generation of rust and swelling on the coated surface isobserved. TABLE 3 Test results Corrosion resistance Salt waterresistance Electro- Water-resistant Maximum Maximum plated Chippingsecondary General peeling width General peeling width film No.resistance adhesiveness part (one side, mm) part (one side, mm) Example31 A1 AA 5 A 6 A 1 32 A2 AA 5 A 4 A 1 33 A2 AA 5 A 4 A 1 34 A4 AA 5 A 4A 0 35 A5 AA 5 A 3 A 0 36 A6 AA 5 A 3 A 0 37 A7 AA 5 A 5 A 2 38 A8 AA 5A 6 A 3 39 A9 AA 5 A 3 A 0 40 A10 AA 5 A 3 A 1 41 A11 AA 5 A 2 A 0 42A12 AA 5 A 2 A 1 43 A13 AA 5 A 2 A 0 44 A14 AA 5 A 2 A 0 45 A15 AA 5 A 2A 0 Comparative example  8 B1 A 2 A 6 A 2  9 B2 C 4 A 13  A 4 10 B3 B 5A 10  A 3 11 C 5 A 8 A 2“4. Coating System 3”

Examples 46 to 60 and Comparative Examples 12 to 14

Each surface of the plated metal materials obtained in the above-shownTable 1 was subjected to alkaline degreasing, washed with water,drained, and dried. Thereafter, a KP color 8000 primer (manufactured byKansai Paint Co., Ltd., a modified epoxy resin-based coating) wasapplied thereon by a bar coater so that a dry film thickness became 5μm, and baked for 20 seconds under conditions so that PMT (maximumreaching temperature of steel plate) became 210° C. to form a coatedfilm. Then, a KP color 1580 white (manufactured by Kansai Paint Co.,Ltd., a polyester resin-based coating) was applied on the primer film bya bar coater so that a dry film thickness became 15 μm, and baked for 40seconds under conditions so that PMT became 215° C. to manufacture eachtest coated plate having an upper-layer coated film.

Comparative Example 15

On a hot dip galvanized steel plate (SGCC Z25 material: JIS G-3302)having a plate thickness of 0.8 mm and treated with a chromate (tradename: COSMER 500, manufactured by Kansai Paint Co., Ltd.), a KP color8000 primer (manufactured by Kansai Paint Co., Ltd., a modified epoxyresin-based coating) was applied by a bar coater so that a dry filmthickness became 5 μm, and baked for 20 seconds under conditions so thatPMT became 210° C. Then, a KP color 1580 white (manufactured by KansaiPaint Co., Ltd., a polyester resin-based coating) was applied on theprimer film by a bar coater so that a dry film thickness became 15 μmand baked for 40 seconds under conditions so that PMT became 215° C. tomanufacture each test coated plate having an upper-layer coated film.

On respective test coated plates obtained in the above Examples andComparative Examples, tests for coated film adhesiveness, corrosionresistance, and moisture resistance were carried out in accordance withthe following test methods. The results are shown in Table 4 below.

(Coated film adhesiveness): The coated surface of the test coated platewas cut by a knife so as to result in each 11 cuts reaching the basemetal lengthwise and crosswise in a grid pattern, whereby 100 blockshaving 1 mm square were formed. Peeled degree of the coated film wasevaluated according to the following standards at the time when acellophane adhesive tape was closely adhered to the grid part and thetape was peeled off instantaneously.

5: No peeling of the coated film is observed.

4: Peeling of the coated film is observed but peeled area is less than10%.

3: Peeled area is from 10% to less than 25%.

2: Peeled area is from 25% to less than 50%.

1: Peeled area is 50% or more.

(Corrosion resistance): After the edge part and rear surface of the testcoated plate having an upper-layer coated film, which had been cut intoa size of 70 cm×150 cm, were sealed, there were provided a 4T foldedpart (a part subjected to a 180° folding, the coated surface beingoutside and four sheets of a spacer having a thickness of 0.8 mmintervening) at an upper part of the test coated plate and a crosscutpart at a lower part of the test coated plate. The coated plate wassubjected to salt spray test for 1000 hours in accordance with JISZ-2371. Then, degree of white rust generation at the 4T folded part,swelling width at the crosscut part, and degree of swelling generationat a general part (a part without processing and cut) were evaluatedaccording to the following standards.

<General Part>

AA: No generation of swelling is observed.

A: Slight generation of swelling is observed.

B: Considerable generation of swelling is observed.

C: Generation of swelling is remarkable and part of the coated film ispeeled.

<Crosscut Part>

AA: One-surface swelling width from crosscut is less than 1 mm.

A: One-surface swelling width from crosscut is from 1 mm to less than 2mm.

B: One-surface swelling width from crosscut is from 2 mm to less than 5mm.

C: One-surface swelling width from crosscut is more than 5 mm.

<Folded Part>

AA: No generation of white rust is observed.

A: Slight generation of white rust is observed.

B: Considerable generation of white rust is observed.

C: Generation of white rust is remarkable and part of the coated film ispeeled.

(Moisture resistance): After the edge part and rear surface of the testcoated plate having an upper-layer coated film, which had been cut intoa size of 70 cm×150 cm, were sealed, a test was carried out inaccordance with JIS K-5400 9.2.2. The test time was 1000 hours underconditions of a temperature in a moisture resistance test instrument of50° C. and a relative humidity of 95 to 100%. The degree of swellinggeneration of the coated film on the test coated plate after the testwas evaluated according to the following standards.

AA: No generation of swelling is observed.

A: Slight generation of swelling is observed.

B: Considerable generation of swelling is observed.

C: Generation of swelling is remarkable and part of the coated film ispeeled. TABLE 4 Electro- Test results plated film Coated film Corrosionresistance Moisture No. adhesiveness General part Crosscut part Foldedpart resistance Example 46 A1 5 AA A A AA 47 A2 5 AA A A AA 48 A2 5 AA AA AA 49 A4 5 AA AA A AA 50 A5 5 AA A A AA 51 A6 5 AA A A AA 52 A7 5 AA AA AA 53 A8 5 AA A A AA 54 A9 5 AA AA A AA 55 A10 5 AA AA A AA 56 A11 5AA A A AA 57 A12 5 AA A A AA 58 A13 5 AA A A AA 59 A14 5 AA A A AA 60A15 5 AA A A AA Comparative Example 12 B1 2 AA B B B 13 82 4 AA B A A 14B3 4 AA A B AA 15 4 AA A B AA“5. Coating System 4”

Examples 61 to 75 and Comparative Examples 16 to 18

Each surface of the plated metal materials obtained in the above-shownTable 1 was subjected to degreasing, washed with water, drained, anddried. Thereafter, each of organic resin coating compositions C1 to C5produced according to the formulations (the formulation ratio is a solidmatter ratio) shown in Table 5 below was applied thereon according tothe combinations shown in Table 6 so that a dry film weight became 0.8g/m², and baked for 20 seconds under conditions so that PMT became 120°C. to manufacture each test coated plate shown in Table 6.

The raw materials of respective notes in Table 5 are the followingsubstances, respectively.

*1) NIKASOL RX-672A: manufactured by Nippon Carbide Industries Co.,Inc., an acryl emulsion

*2) SUPERFLEX 150: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., apolyurethane dispersion

*3) CHEMIPEARL S-650: manufactured by Mitsui Chemicals, Inc., anethylene ionomer resin

*4) ADEKA BONTIGHTER HUX232: manufactured by Asahi Denka Co., Ltd., acarboxyl group-containing urethane dispersion

*5) EPIKOTE 1007: manufactured by Japan Epoxy Resins Co., Ltd., an epoxyresin

*6) DURANATE MF-80: manufactured by Asahi Kasei Corporation, a blockisocyanate resin

*7) SNOWTEX N: manufactured by Nissan Chemical Industries Ltd.,colloidal silica

*8) AEROSIL R-811: manufactured by Nippon Aerosil Co., Ltd., fine powdersilica

*9) CHEMIPEARL W-700: manufactured by Mitsui Chemicals, Inc., apolyethylene dispersion

*10) PTFE powder: a polytetrafluoroethylene resin powder having aparticle size of 2 to 5 μm

Comparative Example 19

On an electrogalvanized steel plate (SECC material with a platingdeposition amount of 20 g/m²: JIS G 3313) having a plate thickness of0.8 mm and treated with a chromate (trade name: Cosmer 500, manufacturedby Kansai Paint Co., Ltd.), an organic resin coating composition C1shown in Table 5 was applied so that a dry film weight became 0.8 g/m²,and baked for 20 seconds under conditions so that PMT became 120° C. tomanufacture a test coated plate. TABLE 5 Organic resin coatingcomposition No. C1 C2 C3 C4 C5 NIKASOL RX-672A*¹⁾ 75 SUPERFLEX 150*²⁾ 75CHEMIPEARL S-650*³⁾ 75 ADEKA BONTIGHTER 75 HUX232*⁴⁾ EPIKOTE 1007*⁵⁾67.5 DURANATE MF-80*⁶⁾ 75 SNOWTEX N*⁷⁾ 12.5 12.5 12.5 12.5 AEROSILR-811*⁸⁾ 12.5 CHEMIPEARL W-700*⁹⁾ 12.5 12.5 12.5 12.5 PTFE powder*¹⁰⁾12.5

On respective test coated plates obtained in the above Examples andComparative Examples, various tests were carried out in accordance withthe following test methods. The results are shown in Table 6 below.

(Test Methods)

(Bare corrosion resistance): After the edge part and rear surface of thetest coated plate were sealed, the coated plate was subjected to saltspray test for 360 hours in accordance with JIS Z-2371. Then, the degreeof rust on the treated film surface was evaluated according to thefollowing standards.

A: Degree of white rust generation is less than 5% of the coated filmarea.

B: Degree of white rust generation is from 5% to less than 30% of thecoated film area.

C: Degree of white rust generation is 30% or more of the coated filmarea.

(Top coat adhesiveness): “MAGICRON #1000 white” (manufactured by KansaiPaint Co., Ltd., an acryl-melamine resin-based coating, white) wasapplied on the test coated plate so that a dry film thickness became 30μm, and baked at 150° C. for 20 minutes to obtain a top-coat coatedplate. After the resulting top-coat coated plate was dipped in a boilingwater for 2 hours, it was allowed to stand at room temperature for 2hours and then the coated surface was cut by a knife so as to result ineach 11 cuts reaching the base metal lengthwise and crosswise in a gridpattern, whereby 100 blocks having 1 mm square were formed. The degreeof peeling of the top-coat coated film was evaluated according to thefollowing standards at the time when a cellophane adhesive tape wasclosely adhered to the grid part and the tape was peeled offinstantaneously.

A: No peeling of the upper-layer coated film is observed.

B: Peeling of the upper-layer coated film is observed in an amount of 1to 9 blocks.

C: Peeling of the upper-layer coated film is observed in an amount of 10or more blocks.

(Fingerprint resistance): After L value, a value, and b value of thecoated film of the test plate were measured using a color-differencemeter “SM color computer MODEL SM-5” (manufactured by Suga TestInstruments Co., Ltd.), white vaseline was applied on the coated film.After vaseline was wiped away with a waste cloth, the L value, a value,and b value were again measured. Then, color difference between beforeand after the vaseline application was calculated and the test plateswere evaluated under the following standards.

A: ΔE is less than 1.0

B: ΔE is from 1.0 to less than 3.0.

C: ΔE is 3.0 or more.

(Lubricity): A plate-like test piece was drawn under a surface pressureof 50 kg/cm² and a drawing rate of 100 m/minute by a tensile testingmachine and a coefficient of dynamic friction at that time wasdetermined to evaluate lubricity according to the following standards.In this connection, this test was carried out on the systems wherein C3,C4, and C5, in which a lubricating function-imparting agent was added toeach organic resin coating composition, were applied.

A: Coefficient of dynamic friction is less than 0.15

B: Coefficient of dynamic friction is from 0.15 to less than 0.30.

C: Coefficient of dynamic friction is 0.30 or more. TABLE 6 Test resultsElectro- Organic Bare plated film resin coating Corrosion Top-coatFinger-print No. composition No. resistance adhesiveness resistanceLubricity Example 61 A1 C1 A A A — 62 A2 C1 A A A — 63 A2 C2 A A A — 64A4 C2 A A A — 65 A5 C3 A A A A 66 A6 C3 A A A A 67 A7 C3 A A A A 68 A8C4 A A A A 69 A9 C4 A A A A 70 A10 C5 A A A A 71 A11 C5 A A A A 72 A12C5 A A A A 73 A13 C2 A A A — 74 A14 C3 A A A A 75 A15 C5 A A A AComparative Example 16 81 C1 B C A — 17 B2 C3 B A A A 18 B3 C5 B A A A19 C1 A B A —“6. Coating System 5”

Examples 76 to 82

A steel bolt was subjected to alkali degreasing and washed with waterand then it was dipped in a 1% sulfuric acid solution at roomtemperature for 30 seconds to effect activation treatment. Thereafter,using a batch-type barrel plating apparatus, plating was conducted in analkaline plating bath containing predetermined metal ions, acorrosion-inhibiting pigment, a corrosion-inhibiting organic compound,and ceramic particles shown in Table 7. The composition of the film wasregulated by changing the concentration ratio of the metal ions in theplating bath, current density, and bath temperature and plated filmthickness was controlled by suitably choosing a plating time. Then, posttreatment was carried out by dipping it in an acidic aqueous solutioncomprising 5 g/l of HNO₃ and 15 g/l of (NH₄)₂ZrF₆, whereby a bolt fortest was manufactured.

Comparative Example 20

A steel bolt was subjected to alkali degreasing and washed with waterand then it was dipped in a 1% sulfuric acid solution at roomtemperature for 30 seconds to effect activation treatment. Thereafter,electrogalvanizing (5 μm) was conducted using a zincate bath (metalzinc: 10 g/l, sodium hydroxide: 120 g/l). Then, it was dipped in ahexavalent chromium-containing chromate solution manufactured by YukenIndustry Co., Ltd.: METASU CY-6 at 25° C. for 10 seconds to effectchromate treatment, whereby a bolt for comparison was manufactured. Theattached amount of the chromate film was from 5 to 6 mg/dm².

Corrosion resistance of the resulting bolt for test was evaluated by thefollowing method. The evaluation results are shown in Table 7.

(Corrosion resistance): A salt spray test (SST) was carried out inaccordance with JIS Z2371 and corrosion resistance was evaluated by thetime required for generation of white rust 10% or red rust 5%. TABLE 7Organic resin*⁵ Corrosion Metal ion*⁴ (g/L) (g/l) inhibitor*⁶ Corrosionresistance Zn Fe Co Ni W R6 R7 F1 F2 F3 White rust 10% Red rust 5%Example 76 78 75 20 20 168 480 77 93 60 10 20 120 504 78 93 60 10 20 120480 79 93 60 10 20 120 600 80 78 75 20 20 30 240 720 81 78 75 20 20 20240 720 82 78 75 20 20 1 168 680 Comparative Example 20  72 240*4: Respective metal ions in Table 7 are supplied from the followingcompounds.

Zn: ZnO

Fe: FeSO₄.7H₂O

Co: CoSO₄.7H₂O

Ni: NiSO₄.7H₂O

W: Na₂WO₄.2H₂O

*5: Respective organic resins in Table 7 are those shown below.

R6: Polyethyleneimine, number average molecular weight of about 3,000.

R7: Polyethylene glycol, number average molecular weight of about10,000.

*6: Respective corrosion inhibitors in Table 7 are those shown below.

F1: K-WHITE 840E, manufactured by Tayca Corporation, condensed aluminumphosphate.

F2: SNOWTEX-O, manufactured by Nissan Chemical Industries, Ltd.,colloidal silica.

F3: 3-Amino-1,2,4-triazole.

While the present invention has bee described in detail and withreference to specific embodiments thereof, it will be apparent to oneskilled in the art that various changes and modifications can be madetherein without departing from the spirit and scope thereof.

This application is based on Japanese Patent Application Nos.2003-410843 (filed Dec. 9, 2003) and 2004-149276 (filed May 19, 2004),the contents thereof being herein incorporated by reference.

INDUSTRIAL APPLICABILITY

Since the organic polymer composite zinc alloy electroplated metalmaterial obtainable using the organic polymer composite zinc alloyelectroplating solution composition of the invention is excellent inadhesiveness to a coating film to be coated thereon, a sufficientcoating adhesiveness and corrosion resistance are obtained withoutsurface treatment such as treatment with a chromate or treatment with aphosphate salt. Thus, not only toxic substances such as a chromium wastesolution generated at the surface treatment can be eliminated but alsothere is a large advantage of cost reduction due to shortening of acoating line.

1. An organic polymer composite zinc alloy electroplating solutioncomposition containing: (A) 1 to 600 g/l of Zn ion, (B) 1 to 600 g/l ofan iron-group-element ion, (C) 0.1 to 200 g/l, in terms of W ion, oftungstic acid-based compound, and (D) 0.5 to 500 g/l of water-soluble orwater-dispersible organic polymer compound having a number averagemolecular weight of 1,000 to 1,000,000.
 2. The organic polymer compositezinc alloy electroplating solution composition according to claim 1,wherein the iron-group-element ion (B) is Fe ion.
 3. The organic polymercomposite zinc alloy electroplating solution composition according toclaim 1, wherein the tungstic acid-based compound (C) is at least onecompound selected from the group consisting of tungstic acid, tungstatesalts, phosphotungustic acid, and phosphotungstate salts.
 4. The organicpolymer composite zinc alloy electroplating solution compositionaccording to any one of claims 1, wherein the organic polymer compound(D) has at least one hydrophilic group selected from the groupconsisting of nonionic hydrophilic groups, anionic hydrophilic groups,and cationic hydrophilic groups.
 5. The organic polymer composite zincalloy electroplating solution composition according to any one of claims1, wherein the organic polymer compound (D) has at least one hydrophilicgroup selected from the group consisting of a hydroxyl group, a sulfonicacid group, a phosphoric acid group, a carboxyl group, an amino group,and an ammonium group.
 6. The organic polymer composite zinc alloyelectroplating solution composition according to any one of claims 1,which further contains 5 to 300 g/l of a corrosion-inhibiting pigmentand/or ceramic particles.
 7. The organic polymer composite zinc alloyelectroplating solution composition according to claim 6, wherein thecorrosion-inhibiting pigment is at least one selected from the groupconsisting of phosphate salts, molybdate salts, metaborate salts, andsilicate salts.
 8. The organic polymer composite zinc alloyelectroplating solution composition according to claim 6, wherein theceramic particles are particles of at least one selected from the groupconsisting of Al₂O₃, SiO₂, TiO₂, ZrO₂, Y₂O₂, ThO₂, CeO₂, Fe₂O₃, B₄C,SiC, WC, ZrC, TiC, graphite, graphite fluoride, BN, Si₃N₄, TiN, Cr₃B₂,ZrB₂, 2MgO.SiO₂, MgO.SiO₂, and ZrO₂.SiO₂.
 9. The organic polymercomposite zinc alloy electroplating solution composition according toany one of claims 1, which further contains 0.01 to 10 g/l of at leastone organic compound selected from the group consisting of alkynes,alkynols, amines or salts thereof, thio compounds, aromatic carboxylicacid compounds or salts thereof, and heterocyclic compounds.
 10. Anorganic polymer composite zinc alloy electroplated metal material, whichis obtainable by electroplating a metal raw material using the organicpolymer composite zinc alloy electroplating solution compositionaccording to
 11. The organic polymer composite zinc alloy electroplatedmetal material according to claim 10, which is obtained by bringing thefilm formed by the electroplating into contact with an acidic aqueoussolution of a compound containing at least one element selected from thegroup consisting of cobalt, nickel, titanium, and zirconium.
 12. Afingerprint-resistant steel plate wherein an organic resin film isdirectly formed on the organic polymer composite zinc alloyelectroplated metal material according to claim 10 without surfacetreatment.
 13. A lubricating steel plate wherein an organic resin filmis directly formed on the organic polymer composite zinc alloyelectroplated metal material according to claim 10 without surfacetreatment.